Detection of physical layer parameter of a master device in an ethernet network

Abstract

In a method for establishing a communication link between a first network interface device and a second network interface device comprises, the second network interface device receives a training signal transmitted by the first network interface device. The training signal is for timing synchronization between the second network interface device and the first network interface device. The second network interface device determines, based on at least one physical characteristic of the training signal, a physical layer (PHY) parameter of the first network interface device. A controller of the second network interface device configures one or more components of the second network interface device to operate in a mode that corresponds to the determined PHY operating parameter of the first network interface device.

What is claimed is: 
     
       1. A method for establishing a communication link between a first network interface device and a second network interface device, the method comprising:
 receiving, at the second network interface device, a training signal transmitted by the rust network interface device as part of establishing the communication link between the first network interface device and the second network interface device, the training signal being for timing synchronization between the second network interface device and the first network interface device; 
 determining, with the second network interface device based on at least one physical characteristic of the training signal, a physical layer (PHY) parameter of the first network interface device, the at least one physical characteristic of the training signal including one or more of i) a continuity of the training signal, ii) an amplitude of the training signal, iii) a fundamental frequency of the training signal and iv) a modulation of the training signal; and 
 configuring, with a controller of the second network interface device, one or more components of the second network interface device to operate in a mode that corresponds to the determined PHY operating parameter of the first network interface device. 
 
     
     
       2. The method of  claim 1 , wherein determining the PHY operating parameter of the first network interface device based on at least one physical characteristic of the training signal comprises:
 measuring the continuity of the training signal, and 
 determining the PHY operating parameter based on the continuity of the training signal. 
 
     
     
       3. The method of  claim 2 , wherein determining the PHY operating parameter based on the continuity of the training signal comprises:
 sampling the training signal at a plurality of times corresponding to a time interval, 
 counting a number of samples corresponding to periods of transmission in the training signal, and 
 determining, based on the samples corresponding to periods of transmission in the training signal, that the training signal has a predetermined continuity characteristic specific to operation with a particular PHY operating parameter among a plurality of PHY operating parameters. 
 
     
     
       4. The method of  claim 1 , wherein determining the PHY operating parameter of the first network interface device based on at least one physical characteristic of the training signal comprises:
 measuring the amplitude of the training signal, and 
 determining the PHY operating parameter based on the amplitude of the training signal. 
 
     
     
       5. The method of  claim 4 , wherein measuring the amplitude of the training signal comprises measuring a peak-to-peak voltage of the training signal. 
     
     
       6. The method of  claim 1 , wherein determining the PHY operating parameter of the first network interface device based on at least one physical characteristic of the training signal comprises determining the PHY operating parameter based on one of i) the modulation of the training signal and ii) the fundamental frequency of the training signal. 
     
     
       7. The method of  claim 1 , wherein determining the PHY operating parameter of the first network interface device based on at least one physical characteristic of the training signal comprises determining the PHY operating parameter based on a combination of two or more of i) the continuity of the training signal, ii) the amplitude of the training signal, iii) the fundamental frequency of the training signal and iv) the modulation of the training signal. 
     
     
       8. The method of  claim 1 , wherein determining the PHY operating parameter of the first network interface device comprises determining a transmission speed of the rust network interface device. 
     
     
       9. The method of  claim 1 , wherein:
 receiving the training signal comprises receiving an initial training signal of a training phase of establishing the communication link between the first network interface device and the second network interface device, and 
 determining the PHY operating parameter of the first network interface device comprises determining the PHY based on one or more samples obtained from the initial training signals. 
 
     
     
       10. The method of  claim 9 , further comprising recovering, with the second network interface device, a clock of the first network interface device from one or both i) the initial training signal and ii) one or more additional training signals received during the training phase of establishing the communication link between the first network interface device and the second network interface device. 
     
     
       11. The method of  claim 1 , wherein determining the PHY operating parameter of the first network interface device based on at least one physical characteristic of the training signal comprises:
 measuring at least one of i) the continuity of the training signal, and ii) the amplitude of the training signal; and 
 determining the PHY operating parameter based on the at least one of i) the continuity of the training signal, and ii) the amplitude of the training signal. 
 
     
     
       12. An apparatus, comprising:
 a second network interface device for coupling the apparatus with a first network interface device via a network link, the second network interface device comprising:
 a transceiver, implemented on one or more integrated circuit (IC) devices, configured to receive a training signal transmitted by the first network interface device over the network link as part of establishing a communication link between the second network interface device and the first network interface device, the training signal being for timing synchronization of the second network interface device with the first network interface device, 
 a physical layer (PHY) operating parameter detector, implemented on the one or more IC devices, configured to determine, based on at least one physical characteristic of the training signal, a PHY operating parameter of the first network interface device, the at least one physical characteristic of the training signal including one or more of i) a continuity of the training signal, ii) an amplitude of the training signal, iii) a fundamental frequency of the training signal and iv) a modulation of the training signal, and 
 a controller, implemented on the one or more IC devices, configured to configure one or more components of the second network interface device to operate in a mode that corresponds to the determined PHY operating parameter of the first network interface device. 
 
 
     
     
       13. The apparatus of  claim 12 , wherein the PHY operating parameter detector is configured to:
 measure at least one of i) the continuity of the training signal, and ii) the amplitude of the training signal; and 
 determine the PHY operating parameter based on the at least one of i) the continuity of the training signal, and ii) the amplitude of the training signal. 
 
     
     
       14. The apparatus of  claim 12 , wherein the PHY operating parameter detector is configured to:
 measure the amplitude of the training signal, and 
 determine the PHY operating parameter of the first network interface device based on the amplitude of the training signal. 
 
     
     
       15. The apparatus of  claim 14 , wherein the PHY operating parameter detector is configured to measure a peak-to-peak voltage of the training signal. 
     
     
       16. The apparatus of  claim 12 , wherein the PHY operating parameter detector is configured to determine the PHY operating parameter of the first network interface device based on one of i) the modulation of the training signal and ii) the fundamental frequency of the training signal. 
     
     
       17. The apparatus of  claim 12 , wherein the PHY operating parameter detector is configured to determine the PHY operating parameter of the first network interface device based on a combination of two or mom of i) the continuity of the training signal, ii) the amplitude of the training signal, iii) the fundamental frequency of the training signal and iv) the modulation of the training signal. 
     
     
       18. The apparatus of  claim 12 , wherein the PHY operating parameter detector is configured to determine the PHY operating parameter of the first network interface device at least by determining a transmission speed of the first network interface device. 
     
     
       19. The apparatus of  claim 12 , wherein:
 the transceiver is configured to receive an initial training signal of a training phase of establishing a communication link between the first network interface device and the second network interface device, and 
 the PHY operating parameter detector is configured to determine the PHY operating parameter of the first network interface device based on one or more samples obtained from the initial training signals. 
 
     
     
       20. The apparatus of  claim 19 , wherein the second network interface device further comprises a clock recovery engine implemented on the one or mom IC devices configured to recover a clock of the first network interface device from one or both i) the initial training signal and ii) one or mom additional training signals received during the training phase of establishing the communication link between the first network interface device and the second network interface device. 
     
     
       21. The apparatus of  claim 12 , wherein the PHY operating parameter detector is configured to:
 measure the continuity of the training signal, and 
 determine the PHY operating parameter of the first network interface device based on the continuity of the training signal. 
 
     
     
       22. The apparatus of  claim 21 , wherein the PHY operating parameter detector is configured to:
 sample the training signal at a plurality of times corresponding to a time interval, 
 count a number of samples corresponding to periods of transmission in the training signal, and 
 determine, based on the number of samples corresponding to periods of transmission in the training signal, that the training signal has a continuity characteristic specific to operation with a particular PHY operating parameter among a plurality of PHY operating parameters.